Vise Design Fits in Tight Spots and is 3” Long and Opens to 1-1/2". Tool are used to relieve clamp spring pressure in very tight spots. Vise is often left in place, with the clamp compressed, during service. Ramp on jaws guides tab of clamp into correct position and traps it in the slot for safety. Tighten knurled knob by hand or use 1/4" drive ratchet. Compact design works great in confined spaces. The small size works especially well on heater hose clamps.